Different users have different interaction skills and experience in using computer-based systems. Some users may need extra guidance and more explicit instructions. Other users may not need any instructions since they follow the instructions from memory, or may be simply better skilled to interact with a system in a more efficient way regardless of their past interaction experience. This variance of user interaction skills creates difficulty in designing “one size fits all” user interfaces that will be suitable to a wide range of users. Furthermore, effective adaptability based on user skills and experience is not available in existing user interfaces.
This is particularly evident in conversational systems, where interaction management is known as dialog management, and is sequential by definition. The usability of a conversational system is therefore greatly affected by the dialog management method. A system that can not quickly adapt to the interaction skills of the user will easily result in slow tedious interaction for advanced users, and alternatively will be unusable for novice users.